1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to a nano imprint master and manufacturing the same, and more particularly, to a method of manufacturing a nano imprint master by which time and costs required for manufacturing the nano imprint master can be reduced without the need for performing a process of removing a metal conductive layer, and a nano imprint master manufactured using the method.
2. Description of the Related Art
Enormous information is pouring as the modern age is called an information-oriented age. Thus, a study for a high dense recording medium for recording enormous information has been briskly proceeded.
Methods of patterning micropatterns of a mask or master on a high dense recording medium include a photolithography technology and a nano imprint lithography technology.
In a photolithography technology, there are problems, such as astronomical costs of equipment, complexity of a device, and difficulty of installation and maintenance, and it is difficult to reproduce in large quantities micropatterns equal to or smaller than 50 nm by one shot. Contrary to this, according to a nano imprint lithography technology, micropatterns can be easily and simply formed and recording media can be reproduced in large quantities with low costs. Thus, the nano imprint lithography technology is usually used in generating micropatterns of a recording medium.
Micropatterns reproduced by nano imprinting are patterns in which patterns of a nano imprint master are transferred without changes. How to produce the nano imprint master very elaborately and easily is most important in the nano imprint lithography technology.
FIGS. 1A-1C illustrate a related art nano imprint process. As illustrated in FIGS. 1A-1C, when a nano imprint process is performed using a nano imprint master 20, firstly, the nano imprint master 20 is disposed on a substrate 10 as shown in FIG. 1A. Next, when ultraviolet (UV) light is irradiated, a polymer resin formed on the substrate 10 is molten, and micropatterns of the nano imprint master 20 are transferred as shown in FIG. 1B. Next, if the substrate 10 is ashed after the nano imprint master 20 is removed from the substrate 10, a recording medium in which micropatterns are formed on the substrate 10 can be obtained as shown in FIG. 1C.
In this case, transparent quartz or glass is used in forming a master substrate used in nano imprinting. This is because UV light must be delivered to and transmitted through both a portion in which patterns of the nano imprint master are formed and a portion in which the patterns of the nano imprint master are not formed so that the polymer resin can be cured.
If there is an opaque portion in part of a region of the nano imprint master, UV light cannot be transmitted through the opaque portion and polymer remains in a corresponding portion in a flowing state. If the nano imprint master is separated from the polymer resin in this state, an uncured polymer resin sticks to the nano imprint master and is detached from a cured polymer resin together with the nano imprint master so that the nano imprint process cannot be properly performed. Thus, since the nano imprint master must be maintained overall in a transparent state, a quartz substrate is commonly used in the nano imprint process.
FIG. 2 is a flowchart illustrating a related art method of manufacturing a nano imprint master. Hereinafter, a method of manufacturing a nano imprint master having micropatterns will be described with reference to FIG. 2.
Firstly, a master substrate is prepared in operation S20. Next, chromium is deposited on a top surface of the master substrate through sputtering in operation S21. Subsequently, an electron beam resist is applied onto the chromium layer in operation S22, and the electron beam resist is patterned using an electron beam exposure device in operation S23.
Subsequently, after the chromium layer is dry etched using the resist coating layer in which micropatterns are formed, as a mask in operation S24, the master substrate is dry etched so that the micropatterns formed in the chromium layer can be transferred to the master substrate in operation S25.
Last, the resist coating layer is stripped or ashed in operation 526, and the chromium layer is completely removed through wet etching and then is cleaned in operation S27, thereby obtaining a nano imprint master in operation S28.
The chromium metal layer is deposited on the master substrate in operation S21, so as to remove electric charges occurring when electron beams are irradiated to the master substrate and the resist formed of dielectric materials, respectively, in the operation of forming patterns using electron beams.
That is, if electric charges are generated in the master substrate and the resist, polarization, in which one surface of the master substrate and an opposed surface thereof have different polarities, occurs. This polarization may cause distortion of micropatterns formed in the mater substrate. In order to prevent polarization, the electric charges are grounded to the outside along the surface of the chromium metal layer and are removed.
According to the above-described related art method of manufacturing a nano imprint master, the chromium metal layer is deposited on the master substrate and then must be etched in a subsequent process and after the master substrate is patterned, the chromium metal layer must be removed. In this way, the method is complicated so that enormous time and costs are required for manufacturing the nano imprint master.
In addition, since the nano imprint master is formed of hardened quartz or glass, when the surface of a substrate on which patterns are imprinted is curved, contact between the nano imprint master and the substrate is nonuniform so that nano imprinting is not uniformly performed and damages may occur in the master used in nano imprinting.